Hammer-drill.



D; S. WAUGH.

HAMMER DRILL. APPLICATION FILED JULY 20,1906.

vPateted-ApI.' 2,0, 1909.

i To all whom imay concern: l

' mechanism for controlling the supply and 'thc rear end .of thecylinder', said hood havthe rear'wall. The hood in 'the torniot con-.citizen of the United States, residing in the lof reference markedthereon, which form a `cylinder member.

ton member at the end of its return stroke,

`responding'paits .in.a.ll the figures ot the drawings.

' ljneinber., G is employed having a piston cylinder member (iis-avalve" casingll hav- UNITED sfrariisV Plriinfr DANIEL S. WAUGH`, OFDENVER, COLORADO., ASSIGNOR TO THEDENVER ROCK DRILL AND MACHINERYCOMPANY, OF DENVER, COLORADO.

HAMMER-DRILL.

Specification of Letters Patent.

Patented April 20, 1909.

Application leo. July 20, 19GB. Serial No. 327,1118.

Be it known that I,- Dxzviign S. WAiein'a city and county of Denver andState ot` Colorado, have invented certain new and useful Improvements nHammer-Drills; and I do declare the vfollowing to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the` same, referencebeing had to the accompanying drawii'igs` and to the letters and figurespartot' this specification.

The present invention relates to hammer drills, and more particularly tothe valve exhaust lof the motive fluid to and from the It Will beobvious that the invention is not necessarily limited to drills, but maybe employedtor pneumatic or motive fluid hammers generally.

In the accompanying drawings Figure 1 is a longitudinal sectional viewthrough a hammer, showing the novel mechanism. F ig. 2 is an enlargedsectional view through the rear portion of the saine, illustrating theosit'ion of the valve during the exhaustig. 3 is a similar view, butshowing the pisandthe valve in posit-ion to admitmotive fluid toetectfthe working stroke of said piston. Fig. l av detail side elevationof the valve. Fig. 5 is a .sectional view'through the valve casing.

Similar reference numerals designa-tc corg lrirthc embodiment disclosed,a cylinder chainber",A in which-'a ,recip'rocatory piston A chuclrf-Qisv carried anall receives a. drillbit A tappet'll is 'interposedbetween the` drill bitand thepiston.A .-'\'biitt.i1ig,agaii1 st the rearend `ofthe inga detachable rear-,wall 12, said rear wall and casingbeing heldin posi-tion .by a hood 13 surrounding the same. and threadedupon ing an internal shoulder 13a abutting against struction shown, hasa mot-ive' tluid chamber 14 arranged in rear of the wall 12 and a.

17, which communicate with .an annular v chamber 1S formed between thehood 13 and the valve casing. Leading from this chamber are rearwardlyextending exhaust passages 19 that open through the rear end of the hoodor head 13, and thus discharge the exhaust air or motive fluidrearwardly and longitudinally ot thel drill as hereinafter explained. l

The front' portion of the valve casing is provided with an annularinternal groovev 20 disposed j'ust in rear of the inlet and exhaustpassage 16, and a seat 21 is formed between said'groove and said passae. A second annular internal groove 22 is -orined within the valvecasing in rear of the groove 20, and a third groove or chamber isprovided in rear of .the groove 22, said'groove or chamber 23 being ofconsiderably greater width than the other grooves.

A motive Huid supply conduit 24 leads tronithe .chamber 1l, through therear wall 12 and valve casing, and communicates with the annular groove20. A combined supply and exhaust conduit leads from the annular groove20, through the front'portion ot the valve casing, and extendslongitudinally through the Wall of the cylinder member, communic'atino,as illustrated at 26 in Fig. 1, with the ront portion of the pistonchamber 7 in advance ot' the piston 8.

,an annular rib 2.8, forming;v afront pressure `surtace 29 against which-themotive iilind supplied, to the channel 20 through the. pas- :sage2i, always acts.. The rib- 2S alsohas `in theopposite sides of'its rearportions .semi-circular pockets 28'. The said -val've is provided with asecond peripheral ribVSO that moves into rcgist with the internal ribtoi-med between the, grooves 22 and 23 of the valve casing, said rib' 30also moving to a position between the side 'walls of the ico exhaust,

rear groove 23, as illustrated in Fig. 3. The valve 27 furtl'iermore.hason its rear end a peripheral rib 31 that operates snugly in the grooveor chamber 23, and has'a rear pressure surface 32 of greater area thanthe pressure surface 29. Finally, the valve :'27 is provided with anexhaust passage 33 that opens through both ends ot the same, the frontand inlet end of said exhaust passage beingalwajvs in alinement with theeombined inlet. and exhaust passage '16, and its rear end being movableinto and ont of eoaetion with a elosure plug 3l formed upon the rearwall l2. This plug is surrounded by a valve seat 35,'into and ont ot'eoaetion. with which the rear end of the valve nieves. When in eoaetionwith such valve as shown in Fig. 3eommunieation between the exhaustpassage 33 and the exhaust port- 17 ot the valve easing, is eut oli'. Atthe/saine time, the rear pressure surl'aee ot the valve 532 is stillexposed in the elianiber or groove i223, as shown in Fig'. 3%, whileeonununieation between said ehamher and the exhaust Channel 33 throughthe valve is out oll'.

'Leading to the rear end of' the Chan'iber or groove Q3 is a conduit 36,said conduit having an inlet port f37 opening into the vision chamber Tat a point that will insure its being covered and uncovered by thepiston during the reeiproeation of the latter. A. vent port- BS ispreferably employed that communicates with the groove or Chamber 225i,and with the exhaust chamber 1S said portbeing covered and uneoveredbythe rib 251 and permitting the escape of any leakage that inay oeeur.rlhe piston 8, as shown, is provided at' its rear end with a. closureplug 3l), and this plug is so arranged that it will pass through theCombined inlet and exhaustpassage 16 and snugly enter the i'ront end otthe.exhaust passage 3?) through the valve. lt .willibe observed that thediameter oi the Closure plug` 39 is less than the diameter of thepassage 1G.

The operation otl the stru'eture is substan t'ially as tollows. Assumingthe parts in the position illustrated in Fig. 3, it will be evident thatmotive (luid, under pressure, will be in the annular groove 20, which atall times is in eonimanif-ation with the supply ronduit llhrough theronduit The motive lluid flows from the groove Qt) through the. eomlnnedsupply and exhaust port 16 into the piston (chamber 7 in rear of thepis-- ton, thus e'lieetiug the 4forward or 'working stroke, of saidpiston. The neoessaryexhaust troni the Chamber 7 in advance of thepiston takes place through the port 2G, the conduit 25, the port 17,Chamber 1S, and ports 19, as will be obvious. lVhen the valve is in thisposition, as shown in Fig. 3, the passage through said valve is closedby the plug 3l and valve seat- 25, but

the rear pressure silrl'aee 32 is exposed so tl at when the piston inits forward movement ina-overs the port 27 of the conduit 3G, motive.fluid under pressure will, 4flow through said eonduit and aetagainstpthe rear pressure surlaee 32. This snriaee is of greater areathan the trout surface 29 and the pressure will etfeet a forwardmoveinent ot the valve until the front end of said 'alve engages theseat Q1. as a consequence, the tiow oi motive fluid from the groove 2Othrough the passage 1o will be eut olf, as shown in Fig. 2, while theexhaust passage 3? through the valve will not only be in eonnnnnieationwith the piston chamber 7 in rear of said piston, but its rear end' willnow be opened and will be in communica tion with the exhaust port. 17oil the valve easing. At. the. same time, the pockets 28 come intoronununieation with the groove Q0, thus permitting mot ive ll uid toflow troni said groove through the pockets into the eonduit 25, whichleads said motive :fluid into the trout end of the piston chamber inadvance ot tl'iepiston. rlhe said piston therefore begins its returnmovement, and the pressure oi the exhaust passing through the pas sages1G and 33 will be suilieient against the rear pressure surlaeelQ to holdthel valve in its foremost position against the pressure of the motivefluid, acting upon the trout pressure sui-tare 2S). The valve thereforemaintains its l'oremost position until the 'plug closure ."9 olf thepiston passes through the port 16, and enters the exhaust passage 33.'Immediately the,exhaust through said passage' is out ott, andcoiisequently the pressure ot' the exhaust. against the surface 32 isimmediately reduced. Therelore the pressure of the motive tluid lagainstthej'ront pressure surface 29 overcomes the reduced pressure against therear surface 3Q, valve rearwardly. This rearward movenient is Aalsoassisted by the compression of the exhaust in the chamber 7 which cannotnow escapo through the passage 33 because. ot the elosure of saidpassage by the plug $59. An air cushion is consequently tornned,

which acts against the front end surface. of the valve, and adds itspressure to thatof the motive. tlnid against the pressure snrfaee 29.The valve is now in its rearmost position again, as illustrated inllioj. 8, and the operation above described is again repeated.

Aln (bonnet-tion with this structure, it is to be noted that while thedirect pressure ot motive fluid from the piston eliamber' 7 through theConduit 36 etteets the forward movement ofthe valve., it is the exhaustpressure against the rear surface 32 that maintains the valve in itsAforward position, and furthermore it'is the reduction of the exhaustpressurev that. permits the motive fluid pressure against the frontpressure surand forces the nieuwe face 29 to move the valve rearwardly,assisted by the compression ofthe exhaust in thev rear end of the pistonchamber 7, after the exhaust passage 33 is closed bythe plug It is alsoto be noted that the exhaust from the instrument is dischargedlongitudinally and rearwardly through the ports 19. This is a decidedadvantage, particularly in drilling machines, as it avoids to a verymaterial degree the raising of dust that Iis necessarily incident to theoperation of drilling machines.

From the foregoing, it is thought that the construction, operation andmany advantages bf the herein described invention will be apparent tothose skilled in the art, without further description, and it will beunder'- stood that various changes in the size, shape, proportion andminor details of construction may be resorted to- Without departing fromthe spirit or sacrificing any of the advantages of the invention.' l.

Having thus fully described my invention, what l claimA as new, anddesire to secure by Letters Patent, is l l l. In an instrument of thecharacter described, the combination with a cylinder member, of aipiston operating therein, and means for controlling the supply of motivetluid to and its exhaust from the cylinder member, said means includinga movable valve having an exhaust lpassage that opens through both endsthereof and a stationary closure plug for one of the open ends, saidvalve being mo vable into and out of coaction with said plug. 4 v

ln an instrument of the character set torth, the combination with acylinder mem# ber, of a4 pistonoperating in the cylinder member, a valvecasing havinga valve chamber, an inlet and exhaust conduit for thecylinder member communicating with one end ot' the valve chamber, and avalve operating in the chamber and having an internal exhaust passageprovided with an inlet that opens through lthe end of the valve andcommunicates with the end of the chamber with which the conduitcommuni,-

cates.

3. ln. an instrument ot' the character set forth/the combination with acylindervinember having. apiston chanlbcr, of a piston operating `in thechamber. a valve casing having a. valve chamber, a combined inlet andexhaust conduit leading from the valve chamber to the piston chamber andconstituting means for supplying motive lfluid to 'the cylinder membervto effect the.`w orking stroke of the, piston, a valve operating, in

the valve cliam'berand controlling thejadmis-v sion and exhaust conduit,said'valve 'having an exhaust apassage, therethrough andbeing providedwith pressure surfaces lof different areas against the smaller of;whichthe motive -tlnidl continuously operates-to urge.

the valve in one direction, means for clos` the ethaust when the. valve.has been to a predetermined` position by the metiera fluid actingagainst the smaller area, andi a second conduit 'leading from thecylinder member for conveying therefrom a portion of the motive fluidutilized in effecting the working stroke of the piston'and directingsuch motive fluid against the surface of greater area of the' valve Lomove said val-.ve 1n a direction opposed the pressure against thesmaller area to out off the supply for the admissionand exhaustcond-uit., said second conduit being covered and uncovered by the pistonduring its movement and when uncovered being in direct communicationthrough the piston chamber with the admission and. exhaustk conduit.

4. In an instrument of the character set forth, `the combination with acylinder meniber anda piston member operating therein,

ot' means for4 controlling the supply of motive fluid .to and itsexhaust fromthev cylinder. member, Said means including a l valvehavingan exhaust passage that opens throuoh both of its ends, andaclosure for one ot said ends, the said valvey being movlai.

able into and outof coaction with the 'i closure, the piston member;constituting a closure for the other end and being movable into and outol coaction there-With.

5. In an instrument of thecharacter set forth, the combination with aycylinder mem ber and a piston member operating therein,` of means forcontrolling thesupply of motive fluid to and its exhaust from thecylinder member, Vsaid means including a valve having an exhaust passagethat opens' through both of its ends, and a stationary closure plug forone of said ends,` said valve being movable into and out of .coactionwith the closure plug', the vpiston member having a `reduced plugconstituting a closure for the other end and being movable into. and outoi' said end. i

6. In an instrument of the character set fortlnthe combination-With acylinder member and a piston member operating therein, of means forcontrolling the supply of motive fluid to and its exhaustv from thecylinder member, said means including a valve having an exhaust 'passageprovided with an` inlet opening through one endof the valve,and adischarge opening through the opposite end, and a stationary closure forthe discharge end, said valve being mov' able linto and out of coactionwith the `closu re', the piston member constituting a closure tor theinletv end of the exhaust pas'- sage and beinglmovable into and out of'coaction therewith.

7. In an instrument of the character set forth, the combination with a;valve casing having an exhaust port at itsy rear end-oi a reciproca-toryvalve operating in. the casing' 13;

and having an exhaiist passage, the discharge end of which opens throughthe rear end of said valve, a rear Wall for the valve- 8. 4In aninstrument of the character setf forth, the combination with a valveeasing having an exhaust port at' its rear end and also having a rearwall provided with. a plug, of a reci [n'ocatory valvc'opcrating in thecasing and having an exhaust passage, the discharge end of which opensthrough the rear end of said valve and receives and is closed by saidplug, the valve being movable away from the plug to establishcommunication between the exhaust passage and the exhaust port, acylinder member arranged in advance ot the valve casing and having openconmmncation therewith, and a piston member operating in the cylindermember and having a reduced plug at its rear end that moves int-o andout of the valve.

9. 1n an instrument of the character set forth, the cou'ibination willia valve casing having an exhaust port at its rear end, of areciprocatory valve operating in the casing and having an exhaustpassage, the discharge end ot which opens through the rear cud of saidvalve, a rear wall for the valve casing having a. valve seat, the valvebeing movable into coaction with the seat. to cut ofi' communicationbetween the discharge end of the exhaust passage and the exhaust portand being movable away from said seat to open said communication, acylinder member, a piston member operating in the cylinder mcmlmr andhaving its movements controlled by the valve, and means for in troducingmotive fluid behind the valve when the exhaust passage therethrough isclosed by the valve seat and when the piston member is in apredetermined position.

l0. ln an instrument of the character set forth, the combination with avalve casing having an exhaust port at its rear end, of a reciprocato'ryvalve operating in the casing and having an exhaust passage, thedischarge end ot which opens through the rear end of said valve, a -rearwall for the valve casing having a valve seat, the valve being movableinto coaction with the seat to eut oli' communication between thedischarge end of the exhaust passage and the exhaust port and beingmovable away from said seat to open said communication, a cylindermember, a piston member operating in the cylinder member and having itsmovements controlled by the valve, and a motive fluid conduit leadingfrom the cylinder member to the valve casing in rear ot the valve, saidconduit being covered and uncovered by the piston memnbcr.

il. ln an instrunufnt oi the character set forth. the combination with avalve casing having a lateral exhaust port at its rear cud, of areciproeatory valve operating in the casing and having an exhaustpassage that opens through both ends, a rear wall -for the valve casinghaving valve seat,

the valve being movable into coaction. with these-at to cut otfcommunication between the discharge end oi. the exhaust passage and theexhaust port and being movable away from said seat to open suchcommunication, a cylinder member, a piston member operatingin thecylinder member and having a reduced end thatis n'iovable into the fexhaust passage of the valve, and a motive the same against. thepressure surface of less a rea, means for conducting the exhaust fromthe cylinder member and carrying it against the opposite surtace ofgreater area to maintain the valve in a predetermined position andagainst movement bythe motive fluid pressure against the snmller surfaceduring the exhaust period, and means thatmoves with the piston .memberand closes the exhaust passage in the valve to stop the exhaust and thusrelieve the surface of greater area o't saidexhaust pressure'.

13. ln an instrument. o'tthe character set forth, the combination with acylinder member and a piston member operating therein, of areciprocatory controlling valve having a front pressure sui-tace and arear pressure surface ot greater arca than the front surface, said valvehaving an exhaust passage,

`means for introducing motive tluid into the cylinder member andmaintaining the same against the front pressure surface, means' forconducting the exhaust from the cylinder member and carrying it againstthe rear surface t'o maintain the valve in the predetermined positionand against movement by the motive fluid pressure against the frontsurface, and. means carried by the piston and enteringl the exhaustpassage for stopping the exhaust and thus relieving the surface ofgreater area of such exhaust Jressure.

14. In an instrument of t e character setl roun ing the exhaust forth,the combination with a cylinder mem-- ber and a piston member,vaivehaving an exhaust .passage opening through both ends, said valvehaving an annular front pressure surface and having a rear ressure*surface at itsrear end surof a reciprocatory ducting motive Huid tothecylinder niember and maintaining it against the front pressure surface,a rear valve seat into land out of coaction with which the rear end ofthe rear surface when the passage is so closed, and means formaintaining a pressure from the exhaust against the rear surface whenthe exhaust passa ge is opened.

l5. In an 4instrument of the character set forth, the combination with acylinder memt ber, of a reciprocatory piston therein, a valve casinglocated at therear end of the cylinder member and having an opencombined su ply and exhaust conduit, a rear wall for said valve casinghaving a valve seat, a reciprocatory valve operating in the valve casingand having an exhaust passage opening through both ends, one end' of'said exhaust passage bfing closed and o cned by the valve seat, aclosurelcarried Yy the piston and movable into and out of the other endof the exhaust passage, said valve having its front portion providedwith an annular pressure surface and having its rear end provided withan opposite pressure surface of greater area than the front surface,means for directing motive fluid to the cylinder member and maintainingit against the front pressure surface, a conduit leadin from thecylinder member to the rear portion of the valve casing and directingmotive fluid against the rear surface of greater area, said conduitbeing covered and uncovered by the piston, and means communicating withthe rear end of the valve casing for carrying oli' the exhaust.

16. In an instrunientof the character set forth, the combination with avalve casing passage and of greater area than the front surface, meansfor rconhaving a combined sup 1y and exhaust passage at one end, theotiier end being. closed and having a plug projecting longitudinallytliereinto, said casing also having a motive fluid inlet port in oneside between its ends, of an automatic reciprocatory valve operating inthe casing and having an exhaust passage extending lon 'tudinallytherethrough and o enin t rough both ends thereof, one en of t e exhaustpassage of the valve being always in communication with the combinedsupply and exhaust passage of the valve casing, the other end beingclosed and opened by the plugupon the reciprocation of the valve. l

17. In an instrument of the character set forth, the combination with avalve casing having an exhaust ort, of a valve having a front pressuresur surface of greater area thanthe front pressure surface, said valvealso having an 'exhaust assage therethroughthatconducts the ex austagainst the rear pressure surface, a cylinder member and a piston memberoperating in the cylinder member, means for leading motive fluid to thevalve casing and maintaining it at all times against the front pressuresurface, means covered and uncovered by the iston member for conductingmotive fluid) from the cylinder member to th'e rear pressure surface, avalve seat exhaust passage of the valve and cut off communicationbetween the saine and the rear pressure surface, and a plug carried bythe piston member and entering the front end ofthe exhaust passage to'close the saine and thus reduce the exhaust pressure against the rearpressure surface when the valve is unseated, formin' an air cushion thatacts with the motive uid against the front pressure surface of the valveto forcekthe valve rearwardly. In testimony whereof I affix my signaturein presence of two witnesses. 4 A DANIEL S. WAUGH.

Witnesses: I

ace and arear pressure-A

